The invention relates to rotary shaft seals, such as those utilized in an internal combustion engine to seal the aperture through which the rear portion of its crankshaft projects.
The prior art teaches the use of an annular aluminum seal housing having a machined bore wherein a molded shaft seal is secured as by press fitting. The resultant seal assembly generates three potential leak paths: the first, between the shaft and the sealing element; the second, between the sealing element and the housing; and the third, between the housing and the engine block/oil pan.
An aluminum rear crankshaft seal housing as taught by the prior art is additionally provided with tapped bores within the plane perpendicular to the main shaft bore for receipt of the engine's oil pan bolts, thereby requiring a costly seondary machining operation.